CVE-2023-54109 in Linux
Summary
by MITRE • 12/24/2025
In the Linux kernel, the following vulnerability has been resolved:
media: rcar_fdp1: Fix refcount leak in probe and remove function
rcar_fcp_get() take reference, which should be balanced with rcar_fcp_put(). Add missing rcar_fcp_put() in fdp1_remove and the error paths of fdp1_probe() to fix this.
[hverkuil: resolve merge conflict, remove() is now void]
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Analysis
by VulDB Data Team • 01/03/2026
The vulnerability identified as CVE-2023-54109 represents a reference count leak within the Linux kernel's media subsystem, specifically affecting the rcar_fdp1 driver used for Renesas R-Car SoC video processing units. This issue resides in the kernel's media framework where the rcar_fdp1 driver handles hardware video processing operations for embedded systems. The flaw manifests in the driver's probe and remove functions where proper reference counting mechanisms fail to maintain balance between acquisition and release operations.
The technical implementation of this vulnerability stems from improper handling of reference counting within the rcar_fdp1 driver's initialization and cleanup paths. When the driver's probe function executes, it calls rcar_fcp_get() to acquire a reference to a hardware component, but fails to ensure that this reference is properly released through corresponding rcar_fcp_put() calls during error conditions or normal removal operations. This creates a scenario where references accumulate without being properly released, leading to resource exhaustion and potential system instability. The issue affects the driver's ability to correctly manage hardware resources and maintain proper kernel state during device lifecycle operations.
The operational impact of this reference count leak can manifest in several ways including gradual memory consumption, potential system hangs, or complete device driver malfunction. When the driver fails to properly release hardware references, it can lead to resource starvation where the kernel's resource management subsystem becomes unable to allocate new references for other drivers or processes. This vulnerability affects embedded systems using Renesas R-Car SoC platforms that rely on the fdp1 video processing unit for multimedia operations. The leak is particularly concerning in embedded environments where memory resources are limited and system stability is paramount. The vulnerability can cause the system to become unresponsive or require manual intervention to clear the resource leak.
Mitigation strategies for this vulnerability involve applying the kernel patch that correctly implements reference counting balance by ensuring rcar_fcp_put() is called in all code paths including error conditions within the fdp1_probe() function and the fdp1_remove() function. System administrators should update to kernel versions containing the fix, typically those released after the vulnerability disclosure. The fix addresses the core issue by ensuring proper reference counting semantics and resolves merge conflicts that may have occurred during development. This vulnerability aligns with CWE-404, which describes improper resource release or unbalanced resource management, and can be categorized under ATT&CK technique T1070.004 for indicator removal and T1566 for social engineering through software supply chain compromises. Organizations should monitor kernel updates and apply patches promptly to maintain system integrity and prevent potential exploitation that could lead to denial of service or privilege escalation scenarios.